角度截断双尺度模型模拟粗糙海面后向散射特性  

Simulation of backscattering from rough sea surface using angular cutoff two-scale model

作　　者：聂丁[1] 张民[1] 殷红成[2] 

机构地区：[1]西安电子科技大学理学院,陕西西安710071 [2]目标与环境电磁散射辐射国防科技重点实验室,北京100854

出　　处：《系统工程与电子技术》2010年第10期2107-2110,共4页Systems Engineering and Electronics

基　　金：国家自然科学基金(60871070)资助课题

摘　　要：针对传统双尺度法中尺度截断波数的选取尚无统一标准可依的情况,提出了一种基于局部入射角划分来选择相应的海面电磁散射计算方法的角度截断双尺度模型:局部入射角小于限定角(约为20°)时,使用基尔霍夫近似计算占主导的镜反射分量;当局部入射角大于限定角时,用微扰法处理小尺度粗糙度所支配的漫射分量。该模型充分利用了基尔霍夫近似和微扰法各自的优点,同时避免了选取截断波数的棘手问题。应用该模型计算并讨论了风速、极化状态以及风向对后向散射系数的影响,并与实验数据进行了比较,取得了较好的吻合,证明了该模型的有效性。According to the problem that there is not a unified guideline for the choice of the cutoff wavenumber for the classical two-scale model（TSM）,an angular cutoff two-scale model is proposed,which is based on the local incident angle division to select the corresponding method for electromagnetic scattering calculation from rough sea surface.When the local incident angle is smaller than the restricted angle（approximately 20°）,the Kirchhoff approximation（KA） is applied to evaluate the specular reflection,which dominates the total scattering in this region;the small perturbation method（SPM） is employed to deal with the diffuse reflection reigned by small roughness as the local incident angle is greater compared with the restricted angle.This new model takes advantage of the superiority of KA and the SPM respectively without dwelling on the tough question about how to choose the proper cutoff wavenumber for the classical TSM.Numerical evaluations for the influence of the wind speed,the polarization as well as the wind direction on the backscattering coefficient from randomly rough sea surface are investigated,the results are in good agreement with the experiment measured data.The validity of the proposed model is then obtained.

关 键 词：双尺度模型 后向散射 粗糙海面 角度截断 

分 类 号：TN011[电子电信—物理电子学]